Things looked really good in Ukraine in 2004. I mean, really good. They do, at least, if you're America.
Victor Yushchenko won the Presidency of Ukraine after a poisoning attempt on his life and a fraudulent runoff that originally gave his opponent the win, prompting massive protests throughout Ukraine known as the Orange Revolution. The West was so thrilled about it that they practically bragged about having had a hand in influencing the outcome.
The West envisioned the final consolidation of the former Soviet Empire into Western hands. With Ukraine secure, Russia would lose influence over a massive population, critical breadbasket, and (most importantly), Russia's only warm-water port of Sevastopol. After the Orange Revolution, the West eyed adding it to NATO, and making the Black Sea a NATO-controlled body of water. Russia's geopolitical position would have been devastated--it would have been resigned to competing with China, India, and Pakistan for influence over Central Asia.
But poor handling of Ukranian politics both by the US and by Yushchenko himself caused him to lose control over parliament rather quickly. Such a loss of control led, of course, to a decline in effectiveness and a further loss of support within Ukraine. NATO did not strike quickly enough. And, indeed, Russia grossly out-maneuvered the West in its 2008 invasion of Georgia, brilliantly repelling both Georgia and Ukraine's incorporation into the American sphere (Georgia's incorporation would have been similarly crushing to Russia's presence in the Caucasus. Had such mismanagement not occurred, Georgia and Ukraine may well be (unpopularly) part of NATO, much as many Middle Eastern states are US allies despite their own internal politics against it. Russia would be dealt its decisive blow into the future--it would not be an influential global power. It would have spent too long focusing on its own border, population, and food security.
The inability to secure gains from pro-Western governments in Ukraine and Georgia will put the West on the defensive with respect to Russia for years to come. Russia will now look to the Baltics to further its influence and buffer--not out of malice, but simply out of geopolitical security concerns. It will be able to make Iran a continuing problem for the US, and will try to keep the US bogged down in Afghanistan. It will become the primary national challenger to the US in the next decade, rather than either collapsing irrecoverably or becoming a pro-Western liberal market country. The latter is unlikely to happen no matter its strength.
Ultimately, this mismanagement was one of the biggest losses for the US, even if not among its poorer performances. The US is in the enviable position of having lots of room to make mistakes and make a mess in its foreign policy (for example, the US wins by the Middle East being a relatively divided and messy region, rather than a united anti-US force). But the situations in Ukraine and Georgia required a precision and skill that the West was not quite able to provide, and it shall pay for that lack of capability in the medium term.